Amphibians are vertebrates (animals with backbones) which are able, when adult, to live both in water and on land. Unlike fish, they can breathe atmospheric oxygen through lungs, and they differ from reptiles in that they have soft, moist, usually scale-less skin, and have to breed in water. Reptiles, such as lizards and turtles, always lay their eggs on land.
Amphibians lay jelly-covered eggs, called spawn, usually in still, fresh water, often among water plants. The resulting young, known as tadpoles - which at first look like legless blobs with tails - are aquatic and have feathery, external gills, but soon develop lungs and legs and leave the water. Adult amphibians spend most of their life on land, usually in damp habitats, only returning to the water to breed in the spring. A few species may be found in water at almost any time of year.
There are three groups of amphibians in the world today - the frogs and toads, the newts and salamanders, and the caecilians (legless burrowing types). However, the only amphibians native to Britain are frogs, toads and newts - two species of frog (there are another two species but these have been introduced from the Continent), two species of toad and three species of newt.